Medical splints have been widely used for many centuries in treating a wide range of medical disorders. There exist several prehistoric skeletons which show broken limbs which had been properly set with splints such that the owner of the limb was able to live a decade or so after breaking the bone before he/she died. The earliest written and pictorial records of splints come from ancient Egypt, where splints were made from reeds, bamboo, and bark padded with linen, and used primarily for treating fractures. The next recorded innovation in splints and splinting technique occurred around 1500 BC when copper splints were used to treat burns. Around 460 BC, no less than the famous Greek medical giant Hippocrates invented, or perhaps was the first to write about, the use of leather straps to hold splints on a fracture. Indeed, Hippocrates' leather straps were the state of the art until relatively recently, when plastic was invented. In North and South America, the historical record of medicinal advancements is sparse compared with the great written histories of Egypt, Greece and Rome, but it is well documented that the use of splints to treat broken bones was a well known and advanced art in many parts of the pre-Columbian Americas at the time of initial contact with Europeans.
During the 1900's, in addition to the discovery of plastic and its multitudinous variety of uses, the medical fight against polio and the necessity of splinting a variety of injuries under less than idea battlefield conditions during the two world wars led to rapid advancement in splinting technology. Today, splints are used to deal with an incredibly wide range of medical problems and disorders, a far cry from the splint's initial use for broken bones. Indeed, splinting has its own classification system and medically-directed standards can be found for treating different situations.
One situation in which splints are used for purposes other than mending broken bones is in the treatment of peripheral neuropathies, a term which encompasses problems with the nerves outside of the brain and spinal cord, specifically the arms and legs. For example, one well known peripheral neuropathy is Guillain-Barre' syndrome, a disease having an incidence rate of approximately 1.7 cases per 100,000 annually, which arises from complications associated with viral illnesses, such as those caused by cytomegalovirus (CMV). Epstein-Barr virus (EBV), and human immunodeficiency virus (HIV), or bacterial infection, including those caused by campylobacter jejuni and Borrelia burgdorferi (Lyme disease).
Other causes of peripheral neuropathies include chronic alcoholism, infection by the varicella-zoster virus, botulism, and poliomyelitis. Peripheral neuropathy may develop as a primary symptom, or it may be due to another disease. For example, peripheral neuropathy is only one symptom of diseases such as amyloid neuropathy, certain cancers, and some inherited neurological disorders. Such diseases may affect the peripheral nervous system (PNS) and the central nervous system (CNS), as well as other body tissues. Peripheral neuropathy may involve damage to a single nerve or nerve group (mononeuropathy) or may involve multiple nerves (polyneuropathy).
Before WWII, nerves were believed to be cords and consequently received little attention. Nerve repair consisted of simple reapproximation and suturing. During WW I, nerve injuries were repaired under tension and risked disruption after repair because of extensive soft tissue injuries and significant infections. During WW II, reoccurrence of these war injuries influenced experimental studies to further investigate the anatomy of the peripheral nerve. Poor outcomes of peripheral nerve damage repair were recognized to be the result of failed axonal regeneration at the site of the repair (Colohan, 1996). An important quality of the peripheral nervous system, as compared to the central nervous system, is its remarkable ability to recover after an injury through remyelination and regeneration of the axon (Grant, 1999).
Nerves can also be affected by injury from mechanical, thermal, chemical or compression means, causing ischemia. The prognosis for recovery from these peripheral nerve injuries depends upon which structures of the nerve were damaged i.e., axon, endoneurium, perineurim, epineurium) and how much of the nerve was damaged. (Malick, 1984; Kasch, 1984)
Classification of nerve injury is based on damage sustained by the nerve components, nerve functionality, and the ability for spontaneous recovery (Grant, 1999; Greenfield, 1997; Ristic, 2000). Seddon (1943) published his three classification of nerve injuries, and Sunderland (1951) expanded his grading system to five (Ristic, 2000).
Neuropathy involves damage to the axon of the nerve cells wherein degeneration of the axon or its surrounding myelin sheath slows or blocks nerve signal conduction at the point of the degeneration. Demyelination (destruction of the myelin sheath around the nerve cell) greatly decreases the speed of impulse conduction through the nerve. Injury mechanisms can include mechanical injury, compartment syndromes, trauma to peripheral nerves, fractures, stretch injuries and neuropathies. Neuropathies can also be caused by the effects of age, an autoimmune disorder, and other chronic diseases, including multiple sclerosis. Neuropathies can further arise due to acute injury to the nerves, such as by severing or blunt force trauma, as can occur in laceration and compression injuries.
The result of damage to the nerve fibers includes the impairment of voluntary movement or function of the area of muscle controlled by the nerve because impulses to the area are blocked. Impaired nerve stimulation to a muscle can result in weakness, decreased movement, loss of control of movement, etc. These effects, in turn, can lead to structural changes in muscle, bone, skin, hair, nails, and body organs due to reduced use of the affected area, immobility, lack of weight bearing, etc. For example, nerve injury can result in muscle weakness, atrophy, and loss of muscle mass. Injury also often results in the loss of sensation and control of the muscles served by the damaged nerves. Such damage can also give rise to infection or structural damage. Changes may include ulcer formation, poor healing, loss of tissue mass, scaring, and deformity. No matter what the cause or type of the neuropathy, the resulting situation is that due to damage to the nerve, a certain part of the body either no longer functions or functions with lesser ability than it originally functioned. The current invention serves to treat these types of problems in a unique and functional manner.
Neuropathies can be either permanent or treatable. Treatment is possible primarily because in some cases where immediate repair or re-growth is not possible, other nerves lying near to those that have been damaged may branch out and connect to the muscles that were previously served by the damaged nerves. The prognosis and speed of peripheral nerve recovery are directly dependent upon such factors as the level and severity of injury, surgical intervention, and the subsequent rehabilitative process. Severe injuries may take months or years for the affected peripheral nerve(s) to recover, if ever. In many cases, it is at least beneficial and in some cases essential that these nerve and muscle group be partially or fully immobilized, or positioned such that they can function with less stress put on the injured part of the body.
In neuropathies affecting muscles of the wrist, hand and fingers, prolonged muscle imbalance due to loss of muscle control can result in joint contractures and over-stretching or extension of denervated muscles. Without proper care, wrist and/or hand function recovery may be limited or may not occur at all. Though the recovery of muscle strength may occur, the loss of sensation (for example, to temperature, pain, or pressure) may not.
The principles behind splinting and caring for a neuropathy are simple and straightforward:
5. Protect denervated muscles from being overstretched. Muscles generally work in a competitive tandem, where one set of muscles plays against another set in moving an appendage one way or the other. When one set of the muscles is weakened due to injury or lack or impairment of neural function, the “innervated” set of muscles can easily overpower and overstretch the weakened or impaired muscles, potentially resulting in further injury and delayed or even reduced recovery possibilities.
6. Prevent undesirable substitution patterns and establish normal hand functions. Without a splint, a patient may adapt to the imbalance and try to maintain the previously easy hand motions by using new and anatomically damaging methods.
7. Prevent joint contractures. Should a patient be allowed to substitute the aforementioned undesirable hand patterns to compensate for the loss of normal hand motion, it is highly likely that the joint will develop a contracture from being taken through less than its full range of motion.
8. Encourage patient compliance. Even the greatest medical strategies for treating peripheral nerve damage will prove useless if the patient doesn't use the splint. Among the important factors in whether a patient will actually use the splint outside of the medical practitioner's line of sight include the attractiveness and appearance of the splint, along with its comfort and ease of use. For example, a number of studies, including Hannah/Hudak (2001), Alsancak (2001) and Ven Lede (2002), show that the most important factor in whether splint compliance was adhered to by patients was aesthetic appearance, with lower profile, functional use, and less structure also being important factors.
Use of a splint is typically employed during the nerve regeneration period of recovery. Splinting helps to minimize the occurrence of deforming joint contractures caused either by hyper-flexing or by hyper-extension of the muscle groups in the affected muscles. Proper splinting also encourages safe and protected use of the injured hand in daily activities. This is true particularly when dealing with wrist and hand injuries, as peripheral neuropathies relating to the wrist and hand frequently require protected regular exercise to have a reasonable chance of partial or total recovery. Thus, there has existed a need for a functional splint that allows for this protected exercise and movement of the wrist/hand with patients who have suffered a peripheral neuropathy.
The invention is particularly directed toward treating patients with radial nerve peripheral nerve damage which allows them to flex their wrist but not extend it, and to flex their fingers but not extend them, a condition generally known as radial nerve palsy. With this condition, a patient whose hand is open can, for example, grasp a can to pick it up, but cannot unclasp his/her fingers or thumb from the can to release it. The invention allows the patient to unclasp his/her fingers from the can, place the can in its desired location, and then be ready to close the hand on another object, as the stays pull the fingers and thumb back into their original, open position. Using the glove also provides wrist support, which is needed to correctly position the patient's wrist for proper usage of the fingers.
In trying to come up with a splint which will assist patients with peripheral and radial nerve damage, it cannot be understated how important the appearance of the splint is in terms of whether the patient will actually use it. A number of studies show that the most important factor in whether a patient will use a particular splint is not how well it works or how comfortable it is, but rather, how it looks. While many in the medical field may find this fact to be disappointing, it remains a fact that cannot be discounted when assessing whether a particular product will help the patient—the best splint in the world is useless if the patient does not use it. As will be seen from some of the prior art, many of the previous attempts to treat peripheral nerve damage were highly expensive and obtrusive machines with many metal wires, springs and clamps which looked more appropriate in a horror movie than on a person. Thus, it is easy to see why many examples of the prior art were not worn substantially outside of the medical practitioner's office.
The prior art has several examples of attempts to resolve this problem. Splints are obviously well know to the medical arts, having been used centuries before the first patent office was formed. The prior art also provides numerous examples of current splints for supporting or treating nerve damage-based injury to voluntary muscle mobility of the hand and digits include supports and splints for use on the hand and digits, however none of these provides a device which can treat a peripheral neurological injury to the hands and/or fingers which is both functional and attractive, comfortable, and user-friendly—in short, a splint that a patient is likely to wear. The prior art also lacks a splint which is adaptable to a range of different sized hands, is relatively inexpensive to produce, and allows the medical practitioner a wide degree of flexibility in treating the neuropathy.
The prior art includes a number of splints which allow for retention and/or strengthening of the fingers. General purpose hand splints, such as those illustrated by U.S. Pat. Nos. 3,938,509 to Barber and 5,466,202 to Stern show the range of splints—from aluminum/foam to inflatable vinyl sheets. These splints, however, do not allow for the selective treatment of peripheral and radial nerve damage as does the current invention. Some, such as U.S. Pat. No. 6,093,162 to Farleigh and U.S. Pat. No. 4,619,250 to Hasegawa, are so unwieldy as to be suitable solely for a medical office, as they require such complex machinery to work that they could not be used at a patient's home or while a patient was walking, driving, or performing other normal daily activities. A number of exercising splints, such as U.S. Pat. Nos. 5,113,849 to Kulken, 6,547,752 B2 to Holland, and 6,059,694 to Villepigue, teach devices used to exercise some combination of the fingers, hand, and thumb muscles and nerves. These patents, however, are unwieldy and are useful mainly for exercising, as opposed to the current invention whose uniqueness comes in large part from its ability to be worn throughout the day and to assist the user in not only exercising and improving the damaged nerves and recovering muscles, but also allowing the user to perform daily functions such as picking up a glass of water to drink, that would be otherwise impossible for the user of the invention to accomplish due to his/her neuropathy. There are also splints which serve to retain or partially retain and immobilize the user's fingers, as seen in U.S. Pat. Nos. 5,921,945 to Gray, and 5,766,142 to Hess. These splints, however, serve only to restrain the fingers rather than encouraging the damaged nerves and muscles to heal, and neither of these splints would allow for a user to clasp and unclasp his/her hand in performing normal hand functions.
There are also a number of unpatented splints on the market today which attempt to address the need for comfortable and functional splint that can be used effectively to treat patients with peripheral nerve damage. For example, there are a number of splints by Oppenheimer and Thomas which use a combination of attachment mechanisms, springs, and wires which provide a patient with a means to unbend the fingers and thumbs after the patient has bent them. These devices, however, as the pictures in their advertisements will make readily apparent, have a large number of delicate springs and wires extending up, out, down and to the side from the patient's wrist and hand up to several inches, thereby both increasing the danger that the splint will be damaged during normal use and restricting the potential uses the patient can make of his/her hand while wearing such a device. These splints are also extremely unattractive, thereby severely decreasing the likelihood that they will be used regularly by the patient.
Finally, the prior art also has several examples of glove-type splints. U.S. Pat. No. 5,014,689 to Meunchen teaches a hand brace with dorsal and palmar hand sections which attach to one another forming a fingerless glove which serves to support the wrist and hand to prevent, reduce, or control carpal tunnel syndrome. This patent does not, however, teach any type of device which relates to the fingers of the hand. Another patent relating to gloves is U.S. Pat. No. 6,010,473 to Robinson. This glove is used by an individual with nerve damage which has hampered the use of the hand, and serves to hold one or more fingers in a set, desired position, with a stated purpose of “provid[ing] comfort to the user while also serving to lessen the obviousness of any hand or finger grotesqueness.” As such, the Robinson patent does not supply a means by which a person with nerve damage to his/her hand can use a glove-like device to improve the functioning of his/her hand.
Commercially available glove-type splints include the Robinson Peripheral Nerve Splint, currently sold by AliMed Inc., is a set of two items, where the inner item is a strip of plastic running over the patient's dorsal hand, from which five “InRigger springs” project, one each to lie dorsally over each finger and the thumb. The “InRigger springs” are metal strips that are resilient enough to “pull” a finger back up after it has been flexed forward. Over this device is fitted a glove, which serves to pull the fingers back up when the metal strips exert their pull. While the Robinson splint avoids the unwieldy and unattractive springs and wires of the Oppenheimer and Thomas splints, it does not provide a complete solution to the problem of providing a simple yet effective method of allowing for flexibility in the treatment of peripheral neuropathies. Since each “InRigger” spring is made with a pre-set tensile strength, there is no adjustability possible. It is also fairly cumbersome to use, as the user first has to align the inner part and then pull over the glove portion, an activity not easy for someone with limited, at best, use of one hand. Finally, although more attractive than the Frankensteinesque Oppenheimer and Thomas splints, the Robinson splint still looks like an overstuffed gardening glove, again, a “look” not likely to cause many patients to use it.
Thus, although the medical field has a number of splints and supports that have been used for treatment of radial nerve damaged muscles, the field still lacks effective splints that have a user friendly, esthetically pleasing low-profile that, at the same time, provide for versatile, life-like operation and allow for easy interchangeability of the components that compensate for muscular and nerve deficits. Thus there has existed a long-felt need for an attractive, comfortable, and user-friendly means of splinting and treating a peripheral neurological injury to the hands and/or fingers. The need extends to a splint which the user is likely to wear, which allows the medical practitioner a wide degree of flexibility in treating the neuropathy, which is adaptable to a range of different sized hands, and is relatively inexpensive to produce.
The current invention provides just such a solution by having a low-profile, simple, orthotic glove with wrist support attachment for treating loss or impairment of extensor and/or flexor muscle function in the upper extremities, particularly in the hands and fingers, due to a peripheral neuropathy. The glove is attractive, comfortable, easy to use, inexpensive to produce, and can be made in versions with or without a wrist support attachment either built into the glove or added as an optional attachment, and can include thermoplastic to provide rigidity. The glove has channels or tunnels into which interchangeable resilient digit extensor elements, or stays, of varying resiliency are placed such that stays of greater or lesser resiliency can be inserted if the degree of the patient's extensor muscle control changes, or the medical practitioner in charge decides that there is a need to change the support and exercise treatment regimens. The splint also has several improvements for thumb support and for supination of the forearm.